Freeway Pollution Causes Brain Damage, Alzheimer's

Your daily freeway commute just got more dangerous. According to researchers at the University of Southern California, even short-term exposure to vehicle pollution can cause significant brain damage similar to that of age-associated memory loss and Alzheimer's disease.

Freeways Are More Polluted Than You Realize

Many studies have been published over the last decade showing the health hazards of freeway air. The heavy concentration of vehicular traffic fill the air with exhaust gas, microscopic particles from burning fossil fuel, degrading tires, and pavement. Most of these particles are only a fraction the size of a human hair, too small for car filtration systems and therefore enter the breathing air inside car cabins and atmosphere. Measurements of pollution taken at freeways are astronomically greater than areas of less vehicular use and the air pollution inside car cabins is even worse, measuring at 2 to 3 times that of the freeway air itself. Furthermore, if you live within three football fields of a freeway, you are likely being exposed to the same levels of pollutants as if you were living in the middle of the freeway itself.

Brain Damage Caused by Pollution

In the study, published today in Environmental Health Perspectives journal, the researchers re-created the freeway pollution environment in a lab setting with the use of actual collected freeway particles. The controlled experiment exposed mice to approximately 150 hours of freeway pollution spread out over the course of 10 weeks. The researchers found that the mice who were exposed to the pollution had significant damage to brain neurons responsible for learning and memory, inflammation associated with premature aging and Alzheimer's disease, and overall impaired brain development.

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"You can't see them, but they are inhaled and have an effect on brain neurons that raises the possibility of long-term brain health consequences of freeway air," said senior author Caleb Finch, Chair of the ARCO/William F. Kieschnick in the Neurobiology of Aging.

Other Adverse Effects of Freeway Air

Brain damage is just one of many adverse outcomes linked to prolonged exposure to polluted freeways. Studies have linked this exposure with higher rates of asthma in children, increased respiratory infections, and a twenty percent increase in preterm and low-birthweight babies. Research has also found that people are two times more likely to die from cardiopulmonary disease if they live close to a freeway as well as have a greater risk for dying from stroke. Bus drivers who spend their workdays on the roads are also more likely to have a number of cancers including those of the respiratory tract, kidneys, bladders, skin, rectum and liver.

The problem, however, is that there is no clear way to protect drivers and urban dwellers against pollution exposure. Many feel that electric cars could help fight this kind of pollution, however Finch is not so sure. “It would certainly sharply decrease the local concentration of nanoparticles, but then at present electrical generation still depends upon other combustion processes — coal — that in a larger environment contribute nanoparticles anyway,” he said. "It's a long-term global project to reduce the amount of nanoparticles around the world. Whether we clean up our cars, we still have to clean up our power generation."